【单选题】听力原文:W: I'm going to leave work early today. There's a debate this evening at 6 o'clock. So I'm going to get an early dinner and head over there. M: Who's debating about what? W: The two candidates fo...
【单选题】已知 K a θ (HAc)=1.8 × 10 -5 , K b θ (NH 3 )=1.8 × 10 -5 , H 2 CO 3 的 K a1 θ =4.2 × 10 -7 , K a 2 θ =5.6 × 10 -11 , H 3 PO 4 的 K a 1 θ =7.6 × 10 -3 , K a 2 θ =6.3 × 10 -8 , K a 2 θ =4.4 × 10 -13 ,欲 配制 p...